Make this powerful HDTV antenna out of cardboard!

Don't let the simplicity fool you. This is a powerful antenna, that easily beats an HDTV antenna I paid $50 for. Refer to the diagram and familiarize yourself with the parts.

You can build it in just 12 steps.

Here's what you need:

-About 3 square feet of cardboard or Foamcor - the longest dimension is 14 inches. (I'm using cardboard from an old computer box for my example.)

-Aluminum foil

-Cable, either 75-ohm coaxial, or 300-ohm twin-lead

-A balun (see the section above)

-Cut the reflector panel out of a sheet of cardboard. There is no pattern for this, just cut out a piece of cardboard or Foamcor 13 inches by 14 inches. If you wish to paint it, it, or glue construction paper to the front, you may do so now. Now, turn it over, apply a little glue, then cut and attach aluminum foil to cover the entire backside.

-Using your pen knife or boxcutter, cut through three sides of the two rectangles you traced onto the reflector.

If you remember from the stencil, the bottom edges of those rectangles were marked with dotted lines. Those are folds, not cuts. If your cardboard or Foamcor is hard to fold, you may make a light score with your knife on the dotted line to make it easier to fold.

These flaps of cardboard will lean out towards the front, and act as a brace for the support brackets. When cutting out the slots where the feet will fit, try to adjust the width of the slots for the material you are using. We want this to be a tight fit, so try to err on the side of making the slots too small. They can always be enlarged later.

-Cut out your other cardboard pieces. Use a small piece of tape to hold the forms in place while you trace around them on your board. You will need two cardboard 'wing sets', two support brackets, and two feet.

After tracing, cut the patterns out of the cardboard, cutting around the INSIDE of the lines (Since you traced the OUTSIDE of the patterns, the correct dimensions are on the inside.)

If you want to paint or color any of these parts, you many do so now. (I'm using a felt pen.) When cutting out the brackets, first do the whole square shape, and then cut out the small slots afterward (I like to cut two sides of the little slots with scissors, then cut the third inside edge with a knife.)

Try to adjust the width of the slots in the brackets for the thickness of the material you are using. We want this to be a tight fit, so try to err on the side of making the slots too skinny. They can always be enlarged later.

-If you look at the cardboard wings pattern, you will see dotted lines where folds need to happen. Use your pattern to mark the correct place for these folds on the back of your wings. You'll have the best results making clean folds if you make light cuts (scores) on these lines. Then fold forward (away from the cut), opening up these light cuts.

The halves of each wing should make an angle of approximately 90 degrees to each other. It may spring back, so adjust these folds until they appear to be staying in the right position. Once you are satisfied, put a bead of glue into the scores. This will help hold the position of the folds.

-Come back when the glue is dry and connect the wiring to the antenna. If connecting twin-lead, separate the wires and strip about 3/4" of the insulation off, then staple the exposed part of the wires to the exact center of the struts between wings. If connecting the balun directly to the antenna, either staple the wires or alternatively, drill or punch a small hole and install a small screw, washers and bolt to the exact center of the strut between wings. Carefully connect the wires from the balun to the screws. (The drawback of screws is that they can never be tightened down hard onto cardboard.)